Typically, such charging devices comprise a mechanism for rotating a support rotor adapted to support the distribution chute. The chute has an elongated chute body e.g. a trough-shaped main part, which defines a sliding channel with an outlet for distributing bulk material in the furnace, and mounting members attached to either side of the elongated main body for removably attaching the distribution chute to the support rotor. For rotating the chute, the support rotor is rotatable about a substantially vertical axis, which generally coincides with the furnace axis. For supporting the chute, the support rotor includes two suspension flanges that cooperate with the chute-mounting members of the distribution chute for removable mounting of the latter. Typically, the suspension flanges are mounted in opposite facing relationship and pivotable on the rotor about an axis perpendicular to the axis of rotation of the rotor to set the pivoting angle of the chute. Examples of such charging devices are described e.g. in U.S. Pat. No. 3,814,403, U.S. Pat. No. 5,022,806 and DE 3342572.
As will be understood, the chute of such charging devices is subject to wear and has to be removable to allow its replacement by a new or refurbished chute. This is because the considerable mass of charge material sliding over the chute causes significant abrasion. Therefore, the configuration used for mounting the chute should allow uncomplicated installation and removal of the chute while ensuring transmission of significant pivoting torques.
For removable mounting, the chute in the device described in U.S. Pat. No. 3,814,403 is provided with lateral suspension journals. On one side it comprises two separate journals, which are received in two separate seats of a suspension flange that is connected to a pivoting mechanism so that this suspension flange can transmit the pivoting torque to the chute. On the opposite side, it comprises a single suspension journal, which can rotate in a seat of a fixed flange. The journals are fixed in the two flanges by means of transverse wedges.
The chute in the device described in U.S. Pat. No. 5,022,806 is also provided with lateral suspension journals. On one side it comprises two separate shaft journals, which are received in a seat of a suspension flange connected to a pivoting mechanism, so that this suspension flange can transmit the pivoting torque to the chute. On the opposite side, it comprises a single journal, which is received in a flange that can rotate on a pivot.
In the device described in German patent application DE 3342572, the chute is provided with two suspension members of special, duckbill shape, which is also illustrated in U.K. patent GB 1 478 527. Each suspension member is received by a corresponding three-point suspension formed by three journals on each suspension flange that can be driven in rotation by the pivoting mechanism. The special shape of the suspension members provides for fixing the chute to the three-point suspension of the suspension flange while allowing the chute to be easily withdrawn by lifting the outlet end of the chute.
A further chute-mounting mechanism in a charging device is disclosed in PCT patent application WO 01/18255. The chute of this device is provided with two lateral suspension arms extending upwards where they are connected to a support rotor. A cylindrical suspension pin is associated with each suspension arm for pivotably connecting it to the support rotor. Each of these two suspension pins is arranged in retractable manner in a bearing of the support rotor. A control lever is connected to the support rotor by means of an articulated joint. A driving mechanism is connected to the control lever to transmit to the latter a pivoting torque. In order to transmit a pivoting torque to the suspension arms, the control lever is provided with a stop, which engages a counterstop provided on the respective suspension arm of the chute.
A disadvantage of the above mounting configurations is that they involve a relatively time-consuming and complicated installation and removal procedure that also typically requires custom-made equipment, i.e. a special purpose device for handling the chute during installation or removal. Such an additional device is described in Luxembourg patent LU 65663 and also in PCT patent application WO 01/18255. This device is required among others because the chute must be held in position underneath the charging device before it can be fixed to the support rotor and because the risk of inadvertently dropping the chute must definitely be avoided.